Silicon's position as the semiconductor of choice in micro/nanoelectronics hinges on its ability to shift to new design paradigms such as opto-electronics. Strategies to produce silicon-based light emitters remain limited, however, relying either on quantum confinement effects or optically-active dopants. We are actively studying the effects of incorporating optically-active Erbium centers into discrete crystalline Si nanocrystals. Such nanocrystals have been prepared via the pyrolysis of disilanein the presence of a suitable Er source. Two rather different types of doped materials have been synthesized to date: one involving a random distribution of erbium centers throughout the nanocrystal; the other forces erbium into a location preferentially-enriched near the surface. This work entails the structural characterization of such materials and their photophysical properties, including spectroscopic measurements under the conditions of high pressure.